a) Field of the Invention
The present invention relates to the protection of painted surfaces, and more particularly to freshly painted surfaces, by the application of a removable plastic film coating. The present invention is well adapted for use in, for example, applying the protective coating to prepainted members, such as panels, boards or the like used in the construction industry.
b) Background Art
There are various situations and/or industrial applications where the surface of various items are pre-painted and then shipped to another location where they are further handled or utilized in some manner, such as making a structure of the like. For example, in the building industry, in many instances wooden boards or planks (e.g., used as siding) are pre-painted and then shipped to the job site where these are used in the construction of the house, building, etc. Because of the nature of the painted surface, certain precautions must be taken in the manner in which these panels are shipped and also used at the location where they are applied to the building structure. Even though a month, or even a year, has passed after the paint has been applied and has cured, if a number of these panels are stacked directly one on top of the other, the painted surfaces of these boards could be damaged. This could occur when there is a combination of pressure and possibly higher temperature, causing the painted surface to stick to the adjacent panel and disfigure the painted surface. A further problem is that in shipment, these panels could be jostled so that there is relative movement between the panels, and this sliding could cause some scratching of the painted surface.
Accordingly, a common prior art method in preparing these panels for shipment is to place between each pair of adjacent panels an intervening layer of a foam plastic material which has surface characteristics so that it will not bond to the painted surface. After a number of panels have been stacked one on top of the other with the foam plastic layers in-between, several ribbons are wrapped around the stack to hold the panels together. Alternatively, instead of using a foam plastic material, a slip sheet (i.e., a plastic non-foam sheet) could be used to provide the separations. To the best knowledge of the applicants, there has not been found a practical way to automate this particular process of stacking the panels with intervening plastic sheets and tying these together for shipment. Thus, it is commonly done manually.
A further problem is that after the panels are shipped to the building site, when the painted panels are removed from the stack, these can be jostled against one another, or against some other object, to cause damage to the painted surface. Or the surface of the panels could be slid over one another causing scratching.
A search of the patent literature has disclosed a number of patents, these being the following:
U.S. Pat. No. 6,159,404 discloses an extrusion coating method for coating of substrates with a film which comprises polyethylene resin and tackifier. The method also requires inclusion of a hygroscopic or hydrophilic additive and is intended as a permanent coating.
European Patent Application 888,908 describes an extrusion coating method for wood substrates which comprises tackified polyolefin resin extrusion coated onto wood substrates to provide a decorative permanent finish, and there is the addition of a second mar resistant layer.
U.S. Pat. No. 6,187,386 (Hundley), discloses an aqueous composition that has a function to prevent water loss during the curing of cement. The composition comprises 5-45% of a wax hydrocarbon substance, 1-10% of polyvinyl alcohol, and additionally an optional biocide, and finally the remaining ingredient is water.
U.S. Pat. No. 6,124,044 describes a method for applying a removable protective film, where the protective film is applied as an emulsion.
U.S. Pat. No. 6,187,377 (Tojo et al.), discloses a suitable paint that is poured onto coated surfaces and a method of application of the composition. In general, the temporary protective coating for the automobile V is applied at station Sd and a spreading station Sa disburses the temporary protective coating over the surface. As described in column 8, lines 45 and following, the paint 18 is poured in a zigzag manner through the nozzles 10 (see FIG. 1). Pressurized air helps disburses the coating more evenly. As shown in FIG. 9, there is a second embodiment where roller 25 is used to disperse the temporary coating evenly.
U.S. Pat. No. 6,110,525 (Stoddard), discloses a coating composition that forms a peelable coating for protecting surfaces from outside elements. The coating has a property of being an ultraviolet absorber and is primarily composed of rubber. In column 5, lines 12-17, the suitable areas of use for the composition are presented.
The description of the preferred embodiment discloses the preferred composition where the rubber particles are in the range from 35-50 percent and the properties are listed in column 2, lines 47-57. Styrene butadiene rubber is a preferred type of rubber used. The other ingredients included in the composition are a UV absorber, antioxidants, pH stabilizers, waxes, defoamers, thixotropic agents and leveling agents.
U.S. Pat. No. 5,573,812 (Moy), discloses a multi layer composite coating compositions. There is a first coat that comprises a film forming composition that can cure or dry. A subsequent coat, or coatings, is or are applied.
U.S. Pat. No. 5,273,787 (Gnatowski), discloses a protective coating, which is a sealer coating containing cyclic epoxy and an anhydride that are adapted to bind to the lignin and cellulose in the wood. After this, the protective coating has a UV protectant is applied thereto.
U.S. Pat. No. 5,143,949 (Grogan et al.), discloses a coating composition for temporary protective coatings adapted to be applied to a variety of surfaces. The composition can be washed off with water.
U.S. Pat. No. 5,070,121 (Hinterwaldner et al.), discloses a solvent free, low monitor, polymerizable pardonable hot melt composition for coating metal, plastic, cellulose and, inorganic material.
U.S. Pat. No. 4,636,543 (Helton), discloses a composition solution that relates to a temporary protective coating used for glass, metal, and nonporous painted surfaces, and is also useful for preventing insect invasion. As disclosed in column 2, line 31-39 the composition comprises generally vinyl chloride resin, a release agent, plasticizers, ketone, and aromatics.
U.S. Pat. No. 4,016,312 (Luthardt), discloses a method of coating a cellulosic substrate with a polymer coating.
U.S. Pat. No. 2,611,153 (Semegen), discloses a composition for a temporary protective coating for rubber, wood, metal, etc. As disclosed in column 1, lines 9-12, the composition can be removed by peeling the layer from the coated surface.